<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script type="text/javascript" src="https://unpkg.com/vue/dist/vue.js"></script>
    <title>下拉框</title>
</head>
<body>

<div id="app">
    <form>
        <fieldset>
            <legend>选择你的国家</legend>
            <!--国家列表-->
            <!--当设置v-model="choosenCountry"，默认选择为空-->
            <select v-model="choosenCountry">
                <option value="1">中国</option>
                <option value="2">日本</option>
                <option value="3">印度</option>
            </select>

        </fieldset>
    </form>
    <div>
        {{choosenCountry}}
    </div>
</div>

<script>
    new Vue({
        el: '#app',
        data: {
            choosenCountry: undefined
        }
    })
</script>
</body>
</html>